1. Field of the Invention
The present invention relates generally to methods and apparatus for converting speaker individualities and, more particularly, to a method and apparatus for speaker individuality conversion that uses speech segments as units, makes the sound quality of speech similar to the voice quality of a specific speaker and outputs speech of various sound qualities from a speech synthesis-by-rule system.
2. Description of the Background Art
A speaker individuality conversion method has conventionally been employed to make the sound quality of speech similar to the voice quality of a specific speaker and output speech of numerous sound qualities from a speech synthesis-by-rule system. In this case, a speaker individuality included in a spectrum of speech controls only some of parameters (e.g., a formant frequency in spectrum parameter, an inclination of the entire spectrum, and the like) to achieve speaker individuality conversion.
In such a conventional method, however, only such a rough speaker individuality conversion as a conversion between male voice and female voice is available.
In addition, the conventional method has another disadvantage that with respect to a rough conversion of speaker individuality, no approach to obtain a rule of converting parameters characterizing speaker's voice quality is established, thereby requiring a heuristic procedure.